On area51 I selected "move topic" in quickmod and was repeatedly clicking ok. Eventually I arrived at a situation when the "are you sure" and "request timed out" boxes were displayed at the same time, and "request timed out" box was on top.

There should be only one of those boxes ever displayed. If an operation succeeds, error UI must be hidden; if an operation fails, the failure message must probably be on top.

Note that I was clicking the ok button in quickmod tools after dismissing the ajax overlay each time.